Well, in the chat we had, David Sinclair didn't specifically say at what age someone should start taking Metformin. We dove deep into the benefits of the drug and how it can potentially help prevent diseases like cancer, Alzheimer's, and even aging itself. But, man, he didn't give a specific age when someone should start taking it. It's one of those things where it's going to depend on your health, your lifestyle, and probably the advice of your doctor who's up to date with the latest research. Always a good idea to chat to the pros before diving into stuff like this.